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Diffstat (limited to 'sh-i18n--envsubst.c')
| -rw-r--r-- | sh-i18n--envsubst.c | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/sh-i18n--envsubst.c b/sh-i18n--envsubst.c new file mode 100644 index 000000000000..e7430b9aa8ec --- /dev/null +++ b/sh-i18n--envsubst.c @@ -0,0 +1,427 @@ +/* + * sh-i18n--envsubst.c - a stripped-down version of gettext's envsubst(1) + * + * Copyright (C) 2010 Ævar Arnfjörð Bjarmason + * + * This is a modified version of + * 67d0871a8c:gettext-runtime/src/envsubst.c from the gettext.git + * repository. It has been stripped down to only implement the + * envsubst(1) features that we need in the git-sh-i18n fallbacks. + * + * The "Close standard error" part in main() is from + * 8dac033df0:gnulib-local/lib/closeout.c. The copyright notices for + * both files are reproduced immediately below. + */ + +#include "git-compat-util.h" +#include "trace2.h" + +/* Substitution of environment variables in shell format strings. + Copyright (C) 2003-2007 Free Software Foundation, Inc. + Written by Bruno Haible <bruno@clisp.org>, 2003. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, see <http://www.gnu.org/licenses/>. */ + +/* closeout.c - close standard output and standard error + Copyright (C) 1998-2007 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, see <http://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +/* If true, substitution shall be performed on all variables. */ +static unsigned short int all_variables; + +/* Forward declaration of local functions. */ +static void print_variables (const char *string); +static void note_variables (const char *string); +static void subst_from_stdin (void); + +int +cmd_main (int argc, const char *argv[]) +{ + /* Default values for command line options. */ + /* unsigned short int show_variables = 0; */ + + trace2_cmd_name("sh-i18n--envsubst"); + + switch (argc) + { + case 1: + error ("we won't substitute all variables on stdin for you"); + break; + /* + all_variables = 1; + subst_from_stdin (); + */ + case 2: + /* echo '$foo and $bar' | git sh-i18n--envsubst --variables '$foo and $bar' */ + all_variables = 0; + note_variables (argv[1]); + subst_from_stdin (); + break; + case 3: + /* git sh-i18n--envsubst --variables '$foo and $bar' */ + if (strcmp(argv[1], "--variables")) + error ("first argument must be --variables when two are given"); + /* show_variables = 1; */ + print_variables (argv[2]); + break; + default: + error ("too many arguments"); + break; + } + + /* Close standard error. This is simpler than fwriteerror_no_ebadf, because + upon failure we don't need an errno - all we can do at this point is to + set an exit status. */ + errno = 0; + if (ferror (stderr) || fflush (stderr)) + { + fclose (stderr); + exit (EXIT_FAILURE); + } + if (fclose (stderr) && errno != EBADF) + exit (EXIT_FAILURE); + + exit (EXIT_SUCCESS); +} + +/* Parse the string and invoke the callback each time a $VARIABLE or + ${VARIABLE} construct is seen, where VARIABLE is a nonempty sequence + of ASCII alphanumeric/underscore characters, starting with an ASCII + alphabetic/underscore character. + We allow only ASCII characters, to avoid dependencies w.r.t. the current + encoding: While "${\xe0}" looks like a variable access in ISO-8859-1 + encoding, it doesn't look like one in the BIG5, BIG5-HKSCS, GBK, GB18030, + SHIFT_JIS, JOHAB encodings, because \xe0\x7d is a single character in these + encodings. */ +static void +find_variables (const char *string, + void (*callback) (const char *var_ptr, size_t var_len)) +{ + for (; *string != '\0';) + if (*string++ == '$') + { + const char *variable_start; + const char *variable_end; + unsigned short int valid; + char c; + + if (*string == '{') + string++; + + variable_start = string; + c = *string; + if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_') + { + do + c = *++string; + while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') + || (c >= '0' && c <= '9') || c == '_'); + variable_end = string; + + if (variable_start[-1] == '{') + { + if (*string == '}') + { + string++; + valid = 1; + } + else + valid = 0; + } + else + valid = 1; + + if (valid) + callback (variable_start, variable_end - variable_start); + } + } +} + + +/* Print a variable to stdout, followed by a newline. */ +static void +print_variable (const char *var_ptr, size_t var_len) +{ + fwrite (var_ptr, var_len, 1, stdout); + putchar ('\n'); +} + +/* Print the variables contained in STRING to stdout, each one followed by a + newline. */ +static void +print_variables (const char *string) +{ + find_variables (string, &print_variable); +} + + +/* Type describing list of immutable strings, + implemented using a dynamic array. */ +typedef struct string_list_ty string_list_ty; +struct string_list_ty +{ + const char **item; + size_t nitems; + size_t nitems_max; +}; + +/* Initialize an empty list of strings. */ +static inline void +string_list_init (string_list_ty *slp) +{ + slp->item = NULL; + slp->nitems = 0; + slp->nitems_max = 0; +} + +/* Append a single string to the end of a list of strings. */ +static inline void +string_list_append (string_list_ty *slp, const char *s) +{ + /* Grow the list. */ + if (slp->nitems >= slp->nitems_max) + { + slp->nitems_max = slp->nitems_max * 2 + 4; + REALLOC_ARRAY(slp->item, slp->nitems_max); + } + + /* Add the string to the end of the list. */ + slp->item[slp->nitems++] = s; +} + +/* Compare two strings given by reference. */ +static int +cmp_string (const void *pstr1, const void *pstr2) +{ + const char *str1 = *(const char **)pstr1; + const char *str2 = *(const char **)pstr2; + + return strcmp (str1, str2); +} + +/* Sort a list of strings. */ +static inline void +string_list_sort (string_list_ty *slp) +{ + QSORT(slp->item, slp->nitems, cmp_string); +} + +/* Test whether a sorted string list contains a given string. */ +static int +sorted_string_list_member (const string_list_ty *slp, const char *s) +{ + size_t j1, j2; + + j1 = 0; + j2 = slp->nitems; + if (j2 > 0) + { + /* Binary search. */ + while (j2 - j1 > 1) + { + /* Here we know that if s is in the list, it is at an index j + with j1 <= j < j2. */ + size_t j = j1 + ((j2 - j1) >> 1); + int result = strcmp (slp->item[j], s); + + if (result > 0) + j2 = j; + else if (result == 0) + return 1; + else + j1 = j + 1; + } + if (j2 > j1) + if (strcmp (slp->item[j1], s) == 0) + return 1; + } + return 0; +} + + +/* Set of variables on which to perform substitution. + Used only if !all_variables. */ +static string_list_ty variables_set; + +/* Adds a variable to variables_set. */ +static void +note_variable (const char *var_ptr, size_t var_len) +{ + char *string = xmemdupz (var_ptr, var_len); + + string_list_append (&variables_set, string); +} + +/* Stores the variables occurring in the string in variables_set. */ +static void +note_variables (const char *string) +{ + string_list_init (&variables_set); + find_variables (string, ¬e_variable); + string_list_sort (&variables_set); +} + + +static int +do_getc (void) +{ + int c = getc (stdin); + + if (c == EOF) + { + if (ferror (stdin)) + error ("error while reading standard input"); + } + + return c; +} + +static inline void +do_ungetc (int c) +{ + if (c != EOF) + ungetc (c, stdin); +} + +/* Copies stdin to stdout, performing substitutions. */ +static void +subst_from_stdin (void) +{ + static char *buffer; + static size_t bufmax; + static size_t buflen; + int c; + + for (;;) + { + c = do_getc (); + if (c == EOF) + break; + /* Look for $VARIABLE or ${VARIABLE}. */ + if (c == '$') + { + unsigned short int opening_brace = 0; + unsigned short int closing_brace = 0; + + c = do_getc (); + if (c == '{') + { + opening_brace = 1; + c = do_getc (); + } + if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_') + { + unsigned short int valid; + + /* Accumulate the VARIABLE in buffer. */ + buflen = 0; + do + { + if (buflen >= bufmax) + { + bufmax = 2 * bufmax + 10; + buffer = xrealloc (buffer, bufmax); + } + buffer[buflen++] = c; + + c = do_getc (); + } + while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') + || (c >= '0' && c <= '9') || c == '_'); + + if (opening_brace) + { + if (c == '}') + { + closing_brace = 1; + valid = 1; + } + else + { + valid = 0; + do_ungetc (c); + } + } + else + { + valid = 1; + do_ungetc (c); + } + + if (valid) + { + /* Terminate the variable in the buffer. */ + if (buflen >= bufmax) + { + bufmax = 2 * bufmax + 10; + buffer = xrealloc (buffer, bufmax); + } + buffer[buflen] = '\0'; + + /* Test whether the variable shall be substituted. */ + if (!all_variables + && !sorted_string_list_member (&variables_set, buffer)) + valid = 0; + } + + if (valid) + { + /* Substitute the variable's value from the environment. */ + const char *env_value = getenv (buffer); + + if (env_value != NULL) + fputs (env_value, stdout); + } + else + { + /* Perform no substitution at all. Since the buffered input + contains no other '$' than at the start, we can just + output all the buffered contents. */ + putchar ('$'); + if (opening_brace) + putchar ('{'); + fwrite (buffer, buflen, 1, stdout); + if (closing_brace) + putchar ('}'); + } + } + else + { + do_ungetc (c); + putchar ('$'); + if (opening_brace) + putchar ('{'); + } + } + else + putchar (c); + } +} |